Foot (weightbearing dorsiplantar view)
The weightbearing dorsiplantar foot radiograph is a specialised projection of the foot. It is key to the assessment of foot alignment and the diagnosis of abnormalities that cause malalignment and foot pain. Nonweightbearing views (e.g. DP foot) are inadequate for the assessment of alignment because the bones of the feet are not in a functional position.
- foot is planted on the detector with the lower leg perpendicular to the floor (weightbearing surface)
- patient distributes weight evenly across both feet
- dosriplantar projection
- base of the third metatarsal
- central beam is angled approximately 15 degrees towards the heel to minimise projecting the tibia and fibula over the hindfoot
- anterior to the skin margins of the distal phalanges
- medial/lateral to the skin margins
- posterior to the calcaneum
- detector size
- 18 cm x 24 cm
- 50-60 kVp
- 3-6 mAs
- 100 cm
Image technical evaluation
- 1st metatarsal has even concavity
- the spaces between the 2nd to 5th metatarsal are equal, yet the bases are overlapping
- intertarsal space between the medial and intermediate cuneiform should be open
Often these views will be requested to rule out lisfranc injuries, remember to explain to your patient it is a natural weight bearing view not a forced one; that is, weight is even distributed
The bases of the metatarsals and the tarsal bones are the most reliable rotation indicator on the DP view.
If the foot is over rotated externally, the metatarsal bases will be heavily superimposed whilst the tuberosity of the navicular bone can be seen in profile.
Over rotation internally will open up the metatarsal bases and the resultant image will bear close resemblance to the medial oblique projection.
Lower limb radiography
- standard foot radiograph series
- weightbearing foot radiograph series
- special foot views
- 1. Thapa MM, Pruthi S, Chew FS. Radiographic assessment of pediatric foot alignment: review. AJR Am J Roentgenol. 2010;194 (6_supplement): S51-8. doi:10.2214/AJR.07.7143 - Pubmed citation
- 2. Ozonoff MB. Pediatric orthopedic radiology. Saunders. (1979) ISBN:0721670342. Read it at Google Books - Find it at Amazon